PDC Dull GradingPDC Dull Grading

Cutting Structure Description of cutter

PDCDullGradingSystemStructure1 2 3 4 5 6 7 8Cutting Structure Description of cutter

wear/damageCutter wear is measured on a numbered scale

0 = no wear/damage 8 = no diamond remaining

I Inner - record the average wear on the inner 2/3 of the bits radius 0 to 8

CuttingStructure B G Remarks

Inner OuterPrimaryDull

LocationBearings

"X"Gage(mm)

OtherDull

ReasonPulled

I O D L B G O R

2/3 of the bit s radius 0 to 8

O Outer - record the average wear on the outer 1/3 of the bits radius 0 to 8

D Primary Dull ConditionA two letter code to indicate the cutting structures A two letter code to indicate the cutting structure s

primary or dominant dull characteristic

BF - Bond Failure BT - Broken Teeth/CuttersCR Cored CT - Chipped Teeth/CuttersDL Cutter Delamination LT - Lost Teeth/CuttersRO - Ring Out WT - Worn Teeth/CuttersNO - No Dull Characteristic

Other Dull CharacteristicsBF Bond Failure BT Broken Cutters

L LocationDenotes the area of the bit where the primary dull

condition is locatedC cone N NoseS shoulder G gaugeA all

BF - Bond Failure BT - Broken CuttersBU - Balled Up CR - CoredCT - Chipped Teeth/Cutters DL Cutter DelamER Erosion HC - Heat CheckingJD - Junk Damage LM - Lost MatrixLN - Lost Nozzle LT - Lost CuttersNO - No Dull Characteristic NR - Not RerunablePN - Plugged Nozzle RO - Ring OutRR Rerunable WO - Washed OutWT - Worn Cutters

B BearingsNot applicable to PDC bits always denote with an X

G GaugeRecord gauge measurement with PDC ring gaugeI denotes in gaugeU d d d i

Reason PulledBHA - Change BHA CM - Condition MudCP - Core Point DMF - Motor FailureDP - Drill Plug DSF - Drill String FailDST - Drill Stem Test DTF - Tool FailureFM - Formation Change HP - Hole ProblemsLIH - Left in Hole LOG - Run LogsPP - Pump Pressure PR - Penetration Rate

Undergauge measurements recorded in mmMeasurement taken at the point of least wear along

entire length of bits gauge region

O Other Dull CharacteristicsA two letter code to indicate an additional dull

characteristic other than the primary dull noted earlier pRIG - Rig Repair TD - Total Depth

TQ Torque TW - Twist OffWC - Weather Conditions WO - Washout in String

earlier

R Reason PulledA two or three letter code to indicate the reason for

pulling the bit out of the hole.